Banning Donald Trump from the UK would allow the US presidential hopeful to be portrayed as a martyr, an MP has warned.
Labour's Paul Flynn insisted the "great danger" of attacking the billionaire businessman is it could "fix on him a halo of victimhood" and boost the cause of his supporters.
The Newport West MP added it would also be a "grave error" for the debate to fuel suspicions that Parliament was acting in an anti-American way.
More than 570,000 people have signed a petition asking the UK Government to bar Mr Trump, arguing there must be action against "hate speech" regardless of a person's wealth or power.
The tycoon, who wants to be the next Republican president, sparked widespread anger after he demanded a block on Muslims entering the US and claimed parts of London were "so radicalised" police were "afraid for their own lives".
During the debate in Westminster Hall, Conservative former minister Andrew Murrison questioned whether any ban would be overturned should the "ridiculous" Mr Trump be elected US president.
He warned it would be an "almighty snub" to those who voted for him if it remained in place.
The MP for South West Wiltshire told Mr Flynn: "The election of your own party leader has shown that remarkable things happen in politics.
"So we have to be alive to the possibility that this ridiculous individual - that is Mr Trump - may be elected as president of the United States.
"In that event, would such a ban be overturned, since it would be one almighty snub to the American citizens to which you have been referring."
Mr Flynn replied: "I'm sure that's absolutely right and the great difficulty that we're in is, in showing disrespect for Mr Trump, it might well be interpreted by supporters and others in America as showing disrespect to the American nation.
"This is not what we're saying. It's one individual that's involved in this.
"But could I put it to the committee that the great danger by attacking this one man is that we can fix on him a halo of victimhood. We give him the role of martyrdom, which can be seen to be an advantage among those that support him.
"A line will go out 'here's these foreigners interfering, telling us what to do' and I think that'd be a grave error if we gave them that situation and allowed our deliberations today to be seen to be anti-American."
Mr Flynn added: "I think our best plan is not to give him that accolade of martyrdom in that way.
"I think we may already be in error in giving him far too much attention in the way that this petition is singled on him but he has done some remarkable things which have caused a great deal of upset."
Earlier, Mr Flynn said Mr Trump's case is similar to that of Dutch politician Geert Wilders, who was seen to be "fomenting hatred against Muslims and guilty of homophobia".
The MP said: "He was banned by the home secretary in 2009 and what happened with Mr Wilders is he appealed to the court and won.
"The result was that he was allowed into the country, the publicity and attention he had for his Islamophobia was multiplied a hundred-fold by the ban and I believe that's something that we should bear in mind."
Conservative Richard Drax (South Dorset) thanked Mr Flynn for introducing the debate in a balanced way, adding: "It seems that anyone who offends anyone - and we all do it almost on a daily basis, sometimes unknowingly, and I do all the time apparently - debate is immediately shut down.
"This is the danger to democracy and I have seen, I believe, in this country, debate about a whole range of things are shut down because they have been labelled as xenophobe, right-wing or left-wing, whichever it may be.
"Let's hear the debate and if it's unreasonable, ignore it."